Aerodynamics
(where science seems to meet magic)
With an estimated top speed in excess of 180mph, high speed stability it an important issue.
Early work included an air dam/splitter at the front and thoughts about improving the already pretty good underbody profile.
Wing Vents
With regard to high pressure build up under the wheel arches, wing vents will be incorporated into the top of the front wings and somewhere at the rear (to be decided). I couldn't find, as usual, vents to my liking so I had to make my own. David at Cutting Edge in Latchingdon made an aluminium mould to my design as this was way beyond my CNC capabilities. The vents are made from carbon fibre.
Rear Wing
High speed lift is still a concern so I am considering a rear wing. I hasten to add that this would be an aerodynamically profiled wing, not an eBay special that just adds drag. Did a fair bit of research and settled on a NACA wing profile that seemed to fit the bill. I can't afford to buy one off the shelf so I will have to make it, carbon fibre with a foam core.
As I like items to perform more than one task whenever possible, I would like this wing to be able to act as an air brake in an emergency. The jury is out as to whether an electric or pneumatic actuator would be best. An electric actuator can be used to adjust the wings angle of attack (AOA) but they have slow extension rates so wouldn't work very well as an air brake operator. Pneumatic actuators are almost instantaneous in comparrison so would work very well air brake wise but they are difficult to make fine adjustments with. It I use an adjustable actuating rod the AOA can be changed manually. Probably answered my own question here but I am still researching.
In order to make a lightweight wing, my method will be to use a dense foam core covered in a couple layers of carbon fibre.
I will cut the foam to the correct profile using the hot wire method. The wooden profiles (shown above) will be attached to each end of the foam to guide the hot wire.
In order to gain some experience I decided to make a wing support. I cut a profile out of aluminium sheet and screwed it to the foam.
The foam core came out pretty well. Covering it with carbon fibre didn't work out so well, but as a proof of concept it is fine. Design has changed considerably since making this but the experience was invaluable.
The next part I tried was a bracket to hold the wing to the upright. Used my prepreg carbon for this task.
First task was to make the mould and this I did in wood on the CNC Mill. Once cut it was sanded, painted and waxed.
I used six layers of carbon and it came out pretty well and fits the wing profile very closely. However, yet another design change has meant that this bracket has also changed so is no obsolete. But at least I now know I can make them in carbon.